maximize power?!

[Andy15r]

so i have a old fox body with a 302, but eventually (soon) i'm looking into getting a 03-04 style Stang. Due to getting married within the next yr or two i wont have the money to buy a cobra like ide like, therefore i think im gonna have to settle with a GT to start with. However, what can I do to this motor to make the same power if not more than what a stock Cobra comes with? What would you guys suggest to do? I really want to put a supercharger on the Stang, but after that im not real familiar with the 4.6L. I dont plan on racing at a drag strip I just want to have a really good looking quick weekend car for me and my "wife" to cruise around in. Any ideas would be great guys!! Thanks

 

[trinity_gt]

Kenne Bell, TorkTech and others make nice PD blower kits for the 2V. Vortech makes a nice centri. I personally favor the PD style blower though a centri might have more peak power potential. To me, area under the curve rules for a street car and you can't beat the right-now boost from a PD in that regard.

To each his own.

 

[Andy15r]

ya i had looked at the Vortech, but i guess i am looking for the most power that can be potentially made so that would be what you suggest then for peak power from a supercharger ? i guess if we wanted more power i could get a turbo but then ide be paying even more money, and have a harder time getting it all tuned and set up. Thats why i'm leaning towards the Supercharger. What could I expect HP wise from just sticking a supercharger on the 4.6L GT ? Im gonna have a lot of ground to cover to make up for the Power my 89 is making right now. But eventually ide like to do more than just put the supercharger on.

 

[trinity_gt]

ya i had looked at the Vortech, but i guess i am looking for the most power that can be potentially made so that would be what you suggest then for peak power from a supercharger ?

All those makers have offerings that will overpower the stock shortblock. You want Cobra power (~390 crank HP) which is easily within the grasp of any of these guys' blowers.

Keep in mind that the Cobra has Manley rods and forged pistons (not to mention knock sensors...) whereas the GT makes due with powdered-metal rods and cast hypereutectic pistons. The GT shortblock is realistically limited to about 450HP before the risk of component failure becomes too high. Even a little 1.7L KB twinscrew can turn the GT shortblock into a boatanchor if you put a small enough pulley on it and don't get the tune just right.

i guess if we wanted more power i could get a turbo but then ide be paying even more money, and have a harder time getting it all tuned and set up.

The limit to GT power isn't the type of forced induction but rather it's the strength of the shortblock. Just about any supercharger out there will meet your requirement for stock (or a tad more) Cobra-level power from a 2V mill. And if you're willing to build that 2V bottom end, you can still up the power as simply as changing the pulley (for example).

What could I expect HP wise from just sticking a supercharger on the 4.6L GT ?

Around 400 at the wheels is normal and fairly safe. Mine was at 385 with a puny 1.7 KB and a 9# pulley but it had (a) the stock manifolds and midpipe and the stock intake right down to the paper filter which probably robbed a few HP, (b) had the incorrect plug gap for a blower set up (0.054" versus 0.035") and (c) had a large vacuum leak due to a mis-plumbed PCV setup. With those issues addressed (still have stock midpipe for emissions testing) it's probably closer to 400 now.

The higher you go from there the shorter the fuse on the shortblock is getting.

 

[Andy15r]

Awesome man! I really appreciate the complete explanation on each question. It's answers like that that make it worth joining a community like this! I wouldn't mind eventually building a motor but if I can make 400hp safely without worrying about destroying the motor I would definetly be satisfied for a while. That's not to shabby for a DD. I think I could appreciae that =D... Again thank you for the help

 

[trinity_gt]

Glad to help. Keep an eye on the thread as others will no doubt chime in and offer great advice too.

With a safe tune -- one that has lots of fuel and little timing -- you can probably rock 400-450 with a good amount of reliability. Although the rods are spindly and comparatively weak, it's detonation that really threatens the shortblock: the pistons are pretty brittle and have very thin top ring lands:

Detonation is almost assuredly going to snap off a portion of that ring land which will start the motor down the slippy slope of self-immolation. To stave off detonation you need to stay conservative with the fuel and spark. This means that if you find yourself tiring of 400rwHP after a while and get the itch to downsize a blower pulley to make some more power, you need to really think about what you're asking the stock parts to do.

There are guys making in excess of 450 on stock parts but statistically speaking, they've got a pin-less handgrenade under the hood. Keep in mind too that a S/C budget should include enough to upgrade fuel system parts. Although my setup is running a stock GT pump with a KB BAP, I'm making few enough HP that it can support this. Even so, I definitely will be looking into ensuring adequate fuel via upgrades in the near future. Fuel starvation because of a loss of fuel pressure can lead to detonation which ... well, you get it.

 

[Andy15r]

Ya the last thing I'll need is to destroy the block. Wouldn't be a good thing =\ lol... I wouldn't mind changing to some after market parts in the process of adding HP but I don't want to sacrifice the block for power for what I'm really lookin for. I could eventually build a block strictly for more than 500 HP. but I think 400-425 safe would suit me just fine by achieving this with the GT block. That way I won't feel underpowered. Realisticlly speaking 400HP is no joke In a small lightweight vehicle. I can't wait to get back from the academy to start really diving into this project head first. Would be pretty sweet to drive around in a "cobra type" stang after all was said and done